1. Field of the Invention
Embodiments described herein relate generally to a sanitary washing apparatus having a bidet washing function for jetting water at the private parts of a female user.
2. Background Art
Sanitary washing apparatuses installed on warm water washing toilet seats are intended to squirt water at the private parts of a user from a nozzle to wash away dirt attached to the private parts and their vicinity. For men, the private parts to be washed are only the anus. For women, the private parts to be washed include the vaginal opening and urethral opening in addition to the anus.
The dirt attached to the anus and its vicinity is attached to the anus and its vicinity during defecation and washed within a relatively short time after attachment. The dirt in this case is washed in the state of being attached during defecation. Hence, the washing area is relatively narrow and limited to the close vicinity of the anus. Furthermore, even if water is squirted at the anus and its vicinity with a strong water force to some extent, the squirt with the strong water force is acceptable to users as long as it ensures sufficient washing power. Hence, typically, in washing the dirt attached to the anus and its vicinity, water with a relatively strong water force is squirted at a relatively narrow washing area.
On the other hand, in washing the woman's delicate area such as the vicinity of the vaginal opening and the vicinity of the urethral opening, the situation is different from that of washing only the vicinity of the anus. That is, it cannot be addressed by squirting water with a relatively strong water force at a relatively narrow washing area. This results from the diversity in the properties of the dirt attached to the woman's private parts and in the timing of the dirt being attached to the woman's private parts.
Specifically, excrements from the human body, such as urine, menstrual blood, and vaginal discharge ejected from the vaginal opening, are all liquid. On the other hand, there are significant differences in their properties, particularly in the viscosity, which significantly affects the performance of washing with water. For instance, urine and vaginal discharge during pregnancy have very low viscosity. On the other hand, typically, vaginal discharge around the ovulatory period has high viscosity. Furthermore, discharge of such excrements from the human body is not necessarily limited to during being seated on the toilet seat. Vaginal discharge and menstrual blood are ejected from the human body independently of time and place. These excrements are ejected from the vaginal opening, and then attached to the skin therearound. In particular, during menstruation, menstrual blood may be spread widely, oxidized by exposure to air, and clotted on the skin surface.
Thus, the type and state of the dirt to be removed by the sanitary washing apparatus are diverse. Hence, for the woman's delicate area, there is demand for expanding the washing area in view of the type and state of the attached dirt. Thus, as a technique for expanding the washing area, there is proposed a human body washing apparatus capable of jetting spirally swirled water from the jetting port of a nozzle (JP-A-2001-090155 and JP-A-2001-090151). By jetting spirally swirled water, the washing range can be adjusted in accordance with the degree of swirling. However, such jetting generates a hollow water flow having a film-like outer periphery. Thus, washing is insufficient in the hollow portion inside the hollow-conic shape.
On the other hand, there is proposed a sanitary washing apparatus capable of compensating for the insufficient washing of the hollow portion (JP-A-2007-100370). In this sanitary washing apparatus, a water flow is jetted also to the hollow portion inside the spirally swirling flow. Thus, while ensuring a wide washing area by the swirling flow, a water flow is added also to the hollow portion. However, in the sanitary washing apparatus described in JP-A-2007-100370, a continuous water flow is additionally jetted to the hollow portion inside the swirling flow. Hence, the washing pressure is high in the central portion of the washing area. This may apply unnecessarily strong stimuli to the woman's delicate area.
Furthermore, there is proposed a private parts washing apparatus capable of varying the washing area by varying the state of interference between the axial jet flow and the tangential jet flow (JP-A-2001-090154). In the private parts washing apparatus described in JP-A-2001-090154, a continuous water flow is jetted in the axial direction. Hence, the water pressure may become too high in the central portion of the washing area.
On the other hand, there is proposed a jetting apparatus capable of jetting water fragments in a swirling state (Japanese Patent No. 3848886). If such water fragments are jetted, the water fragments may drift in air and scatter to the outside of the desired washing area. Then, the drifted water may be attached to the thigh of the user seated on the toilet seat, and the user may feel discomfort.